Field of the Invention
The present disclosure relates to a tunneling diode, which includes a graphene-silicon quantum dot hybrid structure, having improved performance and electrical characteristics by controlling the sizes of silicon quantum dots and the doping concentration of graphene, and a method of manufacturing the same.
Description of the Related Art
Graphene, which has superior optical performance as well as high electrical conductivity, has been increasingly utilized in next-generation displays, such as flexible displays and touch panels, in energy industry fields such as solar cells, in various electronics, such as smart windows, RFIDs, and the like.
Over the past several years, graphene has attracted considerable attention due to potential thereof for the growth of industrial technology as well as the development of basic science. In particular, a technique of manufacturing large-area graphene was recently developed, whereby application possibility thereof is increasing.
Among large-area graphene products, graphene manufactured by chemical vapor deposition (CVD), which is widely used in the industry, has a large area and high transmittance and electrical conductivity, thereby being expected to be applied to transparent electrodes.
To utilize graphene in optical and electronic devices, it is necessary to realize a diode structure which is a basic structure of a semiconductor device. In particular, if graphene is developed as a device having a hybrid structure with a silicon-based material widely used in the current industry, the ripple effect will be very great compared to other materials.
Although various diode types may be manufactured based on a metal-semiconductor or metal-oxide film-semiconductor structure, there are difficulties in applying the metal-semiconductor structure to an optical device due to low transparency of a metal.
Most graphene-silicon junction structures researched to date have demonstrated applicability as tunneling junction diodes in which the metallicity of graphene and semiconductive properties of a bulk monocrystalline silicon wafer are combined.
However, since bandgap energy of monocrystalline silicon cannot be controlled, there have been difficulties in exhibiting ideal performance of a device by combining monocrystalline silicon with graphene.
To determine the performance of a diode, an ideal factor (n) derived from a current-voltage curve of the diode is generally used. An ideal n to function as a diode is known to be 1 to 2.
However, since ideal factors of graphene-monocrystalline silicon junction tunneling diodes which have been developed to date have been reported as very high values, i.e., five or more, there are problems in exhibiting ideal diode performance.
Therefore, there is a need for an ideal and superior device that may control even electrical characteristics of graphene while controlling bandgap energy of silicon.